Common Problems With Calibrachoa Not Blooming

Calibrachoa, commonly known as Million Bells, is a vibrant, trailing plant prized for its abundant, petunia-like blooms that thrive in containers, hanging baskets, and garden beds. However, this colorful favorite can face challenges that affect its performance, including issues with blooming and overall health. Common problems include:

1. Calibrachoa Failing to Bloom

2. Suddenly Stopping its Flower Production

3. Appearing to Decline in Health

In this post, we will explore the most common culprits behind these issues and how to address them effectively. Whether your Calibrachoa isn’t blooming, has suddenly stopped flowering, or appears to be struggling.. we help you understand the root causes and solutions so you can help restore its health and beauty.

By: Reggie Meehan (7/7/25)

Why Is My Calibrachoa Not Blooming?

If your Calibrachoa plants aren't blooming as expected, it can be frustrating. Understanding and addressing issues like sunlight, fertilization, and pruning are key to keeping this plant in peak condition.

Lack of Proper Sunlight

A lack of proper sunlight can significantly hinder the blooms of Calibrachoa. This plant thrives in full sun, requiring at least 6 hours of direct sunlight each day to produce abundant flowers. Without sufficient light exposure, Calibrachoa may develop fewer blooms or fail to flower entirely. Thus, make sure your Calibrachoa is located in a sunny spot where it can receive ample sunlight. If the plant is grown in the ground, check for nearby plants or structures that might be casting excessive shade and trim or reposition them to ensure the Calibrachoa gets the light it needs to flourish.

Improper Fertilization

Nutrient imbalance can hinder Calibrachoa's blooming potential. Excessive nitrogen often results in lush, green foliage but can reduce flower production, while insufficient phosphorus can also inhibit blooming. To promote healthier growth and abundant flowers, use a balanced fertilizer with a higher phosphorus content, such as a 10-30-20 formula, which encourages flowering. You should fertilize once every 2-3 weeks during the active growing season (Spring through early Fall). Avoid over-fertilizing with nitrogen-rich products, as this can lead to excessive leaf growth at the expense of blooms.

Poor Pruning

Poor pruning practices can reduce Calibrachoa's blooming potential, especially when deadheading is neglected. Deadheading, the removal of spent blooms, encourages continuous flowering by redirecting the plant's energy into producing new buds rather than seed formation. To keep Calibrachoa thriving, regularly remove faded flowers throughout the season. Additionally, lightly trimming back leggy growth can help stimulate new branches and promote more blooms, keeping the plant full and vibrant.

Why Did My Calibrachoa Stop Blooming?

If your calibrachoa was blooming beautifully but suddenly stopped, there are a few key reasons this could happen. The most common issues are heat stress, improper watering, and root crowding, and simple steps can be taken to restore vigorous flowering.

Heat Stress

Heat stress can affect Calibrachoa's blooming, but only during periods of extreme temperatures. Although generally heat-tolerant, heat stress can affect Calibrachoa when temperatures exceed 95°F, and it becomes more severe when temperatures climb over 100°F. At these extremes, the plant may slow its growth, reduce blooming, or even enter a semi-dormant state to conserve energy. If this is your current situation, try to provide afternoon shade during heat waves to protect the plant from excessive heat. Additionally, ensure consistent watering to keep the soil adequately moist, helping the plant stay hydrated and healthy during hot weather.

Overwatering or Underwatering

Moisture imbalance, whether from overwatering or underwatering, can significantly disrupt Calibrachoa’s blooming. Too much water can lead to root rot, preventing the plant from absorbing nutrients effectively, while too little water can cause buds to dry out before they have a chance to open. To maintain proper moisture levels, water the plant when the top inch of soil feels dry to the touch. Additionally, ensure pots and garden beds have proper drainage to prevent standing water, keeping the roots healthy and encouraging continuous blooms.

Root Bound Plants

Root-bound plants can hinder Calibrachoa's ability to thrive, especially when grown in small containers. When the roots become tightly packed, nutrient and water absorption is restricted, leading to reduced bloom production. To resolve this, repot the plant into a larger container filled with fresh, nutrient-rich potting mix. Before replanting, gently loosen the root ball to encourage new root growth and ensure better nutrient uptake, helping the plant flourish with healthier blooms.

Why Is My Calibrachoa Dying?

Beyond sunlight, water, and nutrients, Calibrachoa's health can also be affected by disease and pests. Addressing root rot, infestations, and fungal issues promptly is essential to keeping your plant vibrant and blooming throughout the season.

Root Rot

Root rot is a common issue in Calibrachoa caused by excessive moisture around the roots, often leading to fungal infections. This condition can result in yellowing leaves, wilting, and a general decline in plant health as the roots struggle to absorb nutrients. To prevent root rot, ensure proper drainage by using a well-draining soil mix and containers with drainage holes. Additionally, allow the soil to dry slightly between watering sessions to avoid prolonged saturation, helping the plant recover and thrive.

Pest Infestation

Common pests like aphids, spider mites, and whiteflies can harm Calibrachoa by feeding on its sap, which weakens the plant and can lead to stunted growth, yellowing leaves, and reduced flowering. These tiny pests often hide on the undersides of leaves, making them difficult to detect until damage becomes noticeable. To control infestations, apply insecticidal soap or neem oil, both effective and eco-friendly options for eliminating sap-sucking insects. Regularly inspect your plants for early signs of pests, such as sticky residue or tiny moving dots, to catch problems before they spread.

Fungal Diseases

Powdery mildew and botrytis are fungal diseases that can impact Calibrachoa, often presenting as white powdery spots or gray mold on leaves and stems. These infections can weaken the plant, reduce flowering, and spread quickly if left untreated. To prevent these issues, ensure proper air circulation by spacing plants adequately and avoiding overcrowding. If signs of infection appear, applying a fungicide can help control the spread and protect the plant’s overall health.

Go Bring Your Calibrachoa Back to Life!

Calibrachoa not blooming, stopping blooms, or dying can often be traced back to factors like insufficient light, improper watering, nutrient imbalances, and pest issues. By identifying the root cause and applying the proper solutions—such as adjusting sunlight exposure, improving soil drainage, and proper fertilization—you can revive your calibrachoa and enjoy its colorful blooms all season long.